"Next" refers to the occurrence that follows the current. "This" means the occurrence that is present. I'm regards to days, it usually follows a week to week basis, Monday through Saturday.
If its Friday and I say "this Saturday" it's referring to the Saturday in the current week. Tomorrow. "Next Saturday" would be 8 days later.
I see the disconnect. Most people would use the physics definition of sound, you're using the physiologic definition. So yes you're right, however no you're wrong.